To make a payment, registered Serve users choose a recipient (Facebook friends are automatically populated directly into the app's interface) to send money to, enter the dollar amount, and click send.

Once completed, a message is immediately posted to the recipient's Facebook wall providing directions on where to collect their money or to sign up for Serve. Users can also request money through the app, picking the relevant Facebook friend who owes them and sending a request.



Dan Schulman, group president, enterprise growth, American Express, says: "We're constantly working to bring our customers a seamless and consistent payment experience - one that makes sense for our increasingly social lives, whether that's paying a friend back for movie tickets or sending someone money for your share of the vacation house - it can now be sent on Facebook."

AmEx claims the Serve app is unique on Facebook because it allows friends to send, request and receive payments. However, in November PayPal introduced a similar app that lets users send money to friends within the social network. India's ICICI has gone a stage further, with a Facebook app that lets customers carry out banking tasks without leaving the site.